From: Christian Bauer <Christian.Bauer@uni-mainz.de>
Date: Thu, 18 Jul 2002 21:56:54 +0000 (+0000)
Subject: synced to 1.0
X-Git-Tag: release_1-1-0~85
X-Git-Url: https://ginac.de/ginac.git/tutorial/ginac.git?a=commitdiff_plain;h=b461f90b4496e22495b334688b460fd0e21207de;p=ginac.git

synced to 1.0
---

diff --git a/check/exam_clifford.cpp b/check/exam_clifford.cpp
index 73aa132b..71f49dba 100644
--- a/check/exam_clifford.cpp
+++ b/check/exam_clifford.cpp
@@ -160,15 +160,15 @@ static unsigned clifford_check3(void)
 
 	// one-loop vacuum polarization in QED
 	e = dirac_gamma(mu) *
-	    (dirac_slash(l, dim) + dirac_slash(q, dim) + m * dirac_ONE()) *
+	    (dirac_slash(l, dim) + dirac_slash(q, 4) + m * dirac_ONE()) *
 	    dirac_gamma(mu.toggle_variance()) *
 	    (dirac_slash(l, dim) + m * dirac_ONE());
 	e = dirac_trace(e).simplify_indexed(sp);
 	result += check_equal(e, 4*((2-dim)*l*l + (2-dim)*ldotq + dim*m*m).expand());
 
-	e = dirac_slash(q, dim) *
-	    (dirac_slash(l, dim) + dirac_slash(q, dim) + m * dirac_ONE()) *
-	    dirac_slash(q, dim) *
+	e = dirac_slash(q, 4) *
+	    (dirac_slash(l, dim) + dirac_slash(q, 4) + m * dirac_ONE()) *
+	    dirac_slash(q, 4) *
 	    (dirac_slash(l, dim) + m * dirac_ONE());
 	e = dirac_trace(e).simplify_indexed(sp);
 	result += check_equal(e, 4*(2*ldotq*ldotq + q*q*ldotq - q*q*l*l + q*q*m*m).expand());
diff --git a/ginac/tensor.cpp b/ginac/tensor.cpp
index d6ab5a1f..a1daf625 100644
--- a/ginac/tensor.cpp
+++ b/ginac/tensor.cpp
@@ -214,6 +214,13 @@ ex tensmetric::eval_indexed(const basic & i) const
 	const varidx & i1 = ex_to<varidx>(i.op(1));
 	const varidx & i2 = ex_to<varidx>(i.op(2));
 
+	// The dimension of the indices must be equal, otherwise we use the minimal
+	// dimension
+	if (!i1.get_dim().is_equal(i2.get_dim())) {
+		ex min_dim = i1.minimal_dim(i2);
+		return i.subs(lst(i1 == i1.replace_dim(min_dim), i2 == i2.replace_dim(min_dim)));
+	}
+
 	// A metric tensor with one covariant and one contravariant index gets
 	// replaced by a delta tensor
 	if (i1.is_covariant() != i2.is_covariant())
@@ -519,9 +526,6 @@ ex metric_tensor(const ex & i1, const ex & i2)
 {
 	if (!is_a<varidx>(i1) || !is_a<varidx>(i2))
 		throw(std::invalid_argument("indices of metric tensor must be of type varidx"));
-	ex dim = ex_to<idx>(i1).get_dim();
-	if (!dim.is_equal(ex_to<idx>(i2).get_dim()))
-		throw(std::invalid_argument("all indices of metric tensor must have the same dimension"));
 
 	return indexed(tensmetric(), sy_symm(), i1, i2);
 }
@@ -530,9 +534,6 @@ ex lorentz_g(const ex & i1, const ex & i2, bool pos_sig)
 {
 	if (!is_a<varidx>(i1) || !is_a<varidx>(i2))
 		throw(std::invalid_argument("indices of metric tensor must be of type varidx"));
-	ex dim = ex_to<idx>(i1).get_dim();
-	if (!dim.is_equal(ex_to<idx>(i2).get_dim()))
-		throw(std::invalid_argument("all indices of metric tensor must have the same dimension"));
 
 	return indexed(minkmetric(pos_sig), sy_symm(), i1, i2);
 }